MODELING OF THE ADHESION OF BACILLUS CEREUS ISOLATED FROM A DAIRY PLANT AS A FUNCTION OF TIME AND TEMPERATURE

Abstract

Adhesion of Bacillus cereus to stainless steel 304 #4 was evaluated after different times and temperatures of contact. Mathematical model was obtained, which was capable of predicting the adhesion of B. cereus to stainless steel as a function of temperature (4-35C) and time (1-10 days). The increase in temperature from 4 to 35C resulted in an increased number of B. cereus cells attached more than 3 log cycles for an adhesion time of 1 day and more than 4 log cycles for an adhesion time of 10 days, indicating the importance of temperature in adhesion. The maximum number of cells attached to coupons incubated at 35C for 10 days (4.43 log cfu/cm 2 ) was close to the number of cells attached to coupons incubated at 35C for 1 day (4.01 log cfu/cm 2 ). The model obtained represents well the relationship between temperature and rate of adhesion, which is indicated by the statistical indices calculated. PRACTICAL APPLICATIONSThis research shows important information for people dealing with food quality control, quality management, risk assessment, risk management hazard analysis by critical point control and good manufacturing practices, which are well-recognized food safety tools. The number of manufactured foods has widely increased to meet the increasing number of consumers and, sometimes, the hygiene procedures in the food industry are poor or overlooked. It is essential that those responsible for producing food be knowledgeable about the characteristics of the material surfaces used to make the equipment, utensils and conveyors to help in the control of foodborne diseases. The viable alternatives to avoid or minimize food contamination are (1) improving surface quality related to microtopography by improving surface production process; (2) choosing surfaces with better characteristics concerning microtopography to control the adherence process and biofilm formation; and (3) implementing effective controls of cleaning and sanitizing procedures. bs_bs_banner Journal of Food Process Engineering

Mineral composition and bioavailability of calcium and phosphorus from acid whey concentrated by various membrane processes

“…The coupling of diafiltration with nanofiltration caused a decrease in the content of monovalent elements (Na, K), and in that of the microelement Zn. Such an effect of diafiltration used for acid whey concentration was also reported by ROMAN et al (2009ROMAN et al ( , 2012. Bioavailability of dietary supplements, including minerals, can be defined as the proportion of the administered substance capable of being absorbed and available for use or storage (SRINIVASAN 2001).…”

Lipids, pH, and Their Interaction Affect the Inhibitory Effects of Carvacrol against Salmonella Typhimurium PT4 and Escherichia coli O157:H7

“…For the μmax , λ, and viable counts assays, statistical analysis were performed to determine significant differences ( p ≤ 0.05) using analysis of variance (ANOVA) followed by Tukey’s test or Student’s t -test. The results of μmax from turbidity assays were analyzed using response surface methodology (RSM) and the goodness-of-fit and statistical validity of the models generated by RSM were assessed by using one-factor ANOVA, as well as by providing the adjusted determination coefficient ( R 2 adj) and the statistical significance of the regression models ( p -value 0.05) ( Bernardes et al, 2012 ). All analyses were performed using the Statistica software version 7.0 (StatSoft, Inc., Tulsa, OK, United States).…”

Biofilm formation of Enterococcus faecium on stainless steel surfaces: Modeling and control by disinfection agents

“…Studies that used mathematical models to verify the behavior of biofilm formation generally find relative deviation higher than that found in our study. Bernardes et al () found relative deviation from −11.47 to 38.25%. Peña et al () obtained a relative deviation from −19.35 to 15.48% and from −100 to 20% for two different experiments (model with an initial inoculum of 6 log cfu/ml and model with an initial inoculum of 3 log cfu/ml, respectively).…”

“…Studies that used mathematical models to verify the behavior of biofilm formation generally find relative deviation higher than that found in our study. Bernardes et al (2013) found relative deviation from 211.47 to 38.25%. Peña et al…”